This invention relates to cutting tools in which a cutting tool holder releasably holds a replaceable cutting insert composed of an extremely hard cutting material which is discarded and replaced when dull.
Replaceable cutting inserts of the type herein concerned typically include a centrally disposed aperture wherein a screw receivable in the aperture retains the cutting insert in the tool holder.
Precise retention of the cutting insert in the tool holder during high speed rotation thereof is important as respects both positioning accuracy of the insert and safety. The problem is particularly acute when it is desired to position the insert in the holder with the cutting face of the insert substantially free of encumbrances for maximum chip flow.
It is thus a principal object of the present invention to provide a rotary cutter having replaceable cutting inserts with retention means that will insure retention of the insert notwithstanding high rotational speeds of the cutter.
It is a further object of the present invention to provide retention means for such a cutter wherein the cutting faces of the inserts are substantially free of encumbrance for maximum chip flow.